Is a psychological test used to impeach a witness's credibility?

The use of the results of a psychological examination to impeach a witness's credibility is, in the main, disfavored. (See People v. Marshall (1996) 13 Cal.4th 799, 835, 55 Cal.Rptr.2d 347, 919 P.2d 1280.) Evidence Code section 351.1 provides: "(a) Notwithstanding any other provision of law, the results of a polygraph examination, the opinion of a polygraph examiner, or any reference to an offer to take, failure to take, or taking of a polygraph examination, shall not be admitted into evidence in any criminal proceeding, including pretrial and post conviction motions and hearings, or in any trial or hearing of a juvenile for a criminal offense, whether heard in juvenile or adult court, unless all parties stipulate to the admission of such results. [I] (b) Nothing in this section is intended to exclude from evidence statements made during a polygraph examination which are otherwise admissible."